diff --git a/src/game.rs b/src/game.rs
index 8d08dce..49dca76 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -78,11 +78,11 @@ impl CardCounts {
 impl fmt::Display for CardCounts {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         for &color in COLORS.iter() {
-            f.write_str(&format!("{}: ", color,))?;
+            write!(f, "{}: ", color)?;
             for &value in VALUES.iter() {
                 let count = self.get_count(&Card::new(color, value));
                 let total = get_count_for_value(value);
-                f.write_str(&format!("{}/{} {}s", count, total, value))?;
+                write!(f, "{}/{} {}s", count, total, value)?;
                 if value != FINAL_VALUE {
                     f.write_str(", ")?;
                 }
@@ -123,9 +123,7 @@ impl Discard {
 }
 impl fmt::Display for Discard {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        // f.write_str(&format!(
-        //     "{}", self.cards,
-        // ))?;
+        // write!(f, "{}", self.cards)?;
         write!(f, "{}", self.counts)
     }
 }
@@ -387,35 +385,35 @@ impl BoardState {
 impl fmt::Display for BoardState {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if self.is_over() {
-            f.write_str(&format!("Turn {} (GAME ENDED):\n", self.turn))?;
+            writeln!(f, "Turn {} (GAME ENDED):", self.turn)?;
         } else {
-            f.write_str(&format!(
-                "Turn {} (Player {}'s turn):\n",
-                self.turn, self.player
-            ))?;
+            writeln!(f, "Turn {} (Player {}'s turn):", self.turn, self.player)?;
         }
 
-        f.write_str(&format!("{} cards remaining in deck\n", self.deck_size))?;
+        writeln!(f, "{} cards remaining in deck", self.deck_size)?;
         if self.deck_size == 0 {
-            f.write_str(&format!(
-                "Deck is empty.  {} turns remaining in game\n",
+            writeln!(
+                f,
+                "Deck is empty.  {} turns remaining in game",
                 self.deckless_turns_remaining
-            ))?;
+            )?;
         }
-        f.write_str(&format!(
-            "{}/{} hints remaining\n",
+        writeln!(
+            f,
+            "{}/{} hints remaining",
             self.hints_remaining, self.hints_total
-        ))?;
-        f.write_str(&format!(
-            "{}/{} lives remaining\n",
+        )?;
+        writeln!(
+            f,
+            "{}/{} lives remaining",
             self.lives_remaining, self.lives_total
-        ))?;
+        )?;
         f.write_str("Fireworks:\n")?;
         for &color in COLORS.iter() {
-            f.write_str(&format!("  {}\n", self.get_firework(color)))?;
+            writeln!(f, "  {}", self.get_firework(color))?;
         }
         f.write_str("Discard:\n")?;
-        f.write_str(&format!("{}\n", self.discard))?;
+        writeln!(f, "{}\n", self.discard)?;
 
         Ok(())
     }
@@ -550,16 +548,16 @@ impl fmt::Display for GameState {
         f.write_str("======\n")?;
         for player in self.board.get_players() {
             let hand = &self.hands.get(&player).unwrap();
-            f.write_str(&format!("player {}:", player))?;
+            write!(f, "player {}:", player)?;
             for card in hand.iter() {
-                f.write_str(&format!("    {}", card))?;
+                write!(f, "    {}", card)?;
             }
             f.write_str("\n")?;
         }
         f.write_str("======\n")?;
         f.write_str("Board:\n")?;
         f.write_str("======\n")?;
-        f.write_str(&format!("{}", self.board))?;
+        write!(f, "{}", self.board)?;
         Ok(())
     }
 }
diff --git a/src/helpers.rs b/src/helpers.rs
index ce0358c..9895edd 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -1,7 +1,7 @@
 use std::cmp::Eq;
 use std::collections::{HashMap, HashSet};
 use std::convert::From;
-use std::fmt;
+use std::fmt::{self, Write};
 use std::hash::Hash;
 use std::ops::{Index, IndexMut};
 use std::slice;
@@ -268,7 +268,7 @@ impl fmt::Display for SimpleCardInfo {
         //}
         for &value in &VALUES {
             if self.value_info.is_possible(value) {
-                string.push_str(&format!("{}", value));
+                write!(string, "{}", value).unwrap();
             }
         }
         f.pad(&string)
@@ -401,7 +401,7 @@ impl CardInfo for CardPossibilityTable {
 impl fmt::Display for CardPossibilityTable {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         for (card, weight) in &self.possible {
-            f.write_str(&format!("{} {}, ", weight, card))?;
+            write!(f, "{} {}, ", weight, card)?;
         }
         Ok(())
     }
diff --git a/src/simulator.rs b/src/simulator.rs
index db0a1b2..71ffc11 100644
--- a/src/simulator.rs
+++ b/src/simulator.rs
@@ -122,7 +122,7 @@ impl fmt::Display for Histogram {
         let mut keys = self.hist.keys().collect::<Vec<_>>();
         keys.sort();
         for val in keys {
-            f.write_str(&format!("\n{}: {}", val, self.get_count(val),))?;
+            write!(f, "\n{}: {}", val, self.get_count(val))?;
         }
         Ok(())
     }
diff --git a/src/strategies/information.rs b/src/strategies/information.rs
index d91b17d..8ab6c24 100644
--- a/src/strategies/information.rs
+++ b/src/strategies/information.rs
@@ -159,14 +159,14 @@ impl CardPossibilityPartition {
             n_partitions += 1;
         }
 
-        // let mut s : String = "Partition: |".to_string();
+        // let mut s: String = "Partition: |".to_string();
         // for i in 0..n_partitions {
         //     for (card, block) in partition.iter() {
         //         if *block == i {
         //             s = s + &format!(" {}", card);
         //         }
         //     }
-        //     s = s + &format!(" |");
+        //     s.push_str(" |");
         // }
         // debug!("{}", s);